Prevalence of the bacteriological positive pulmonary tuberculosis: Neimeng had the highest prevalence (337.5/100,000); Sichuan (315.5/100,000) and Hainan (301.8/100,000) followed. Beijing had the lowest (22.0/100,000) and Shanghai followed (29.9/100,000). The highest bacteriological positive prevalence was 15.4 times higher than that of the lowest. After standardization, Neimeng still had the highest standardized prevalence (297.5/100,000): Hainan (274.7/100,000) and Sichuan (261.5/100,000) followed. Beijing had the lowest standardized prevalence (12.0/100,000) and Shanghai followed (16.3/100,000). The highest standardized prevalence was 24.8 times higher than that of the lowest.
After standardization, there were nine provinces and regions whose standardized bacteriological positive prevalence was higher than that of the national weighted prevalence (average value). They were Neimeng, Hainan, Sichuan, Xinjiang, Hunan, Hubei, Anhui, Ningxia and Jiangxi.
Prevalence of the smear positive pulmonary tuberculosis: Neimeng had the highest prevalence (285.2/100,000); Hainan (260.0/100,000) and Sichuan (217.4/100,000) followed. Beijing had the lowest (16.5/100,000) and Shanghai followed (26.7/100,000). The highest bacteriological positive prevalence was 17.3 times higher than that of the lowest.
After standardization, Neimeng still had the highest standardized prevalence (253.1/100,000); Hainan (237.5/100,000) and Xinjiang (189.3/100.000) followed. Beijing had the lowest standardized prevalence (9.7/100,000) and Shanghai followed (12.4/100,000). The highest standardized prevalence was 25.3 times higher than that of the lowest.
After standardization, there were nine provinces and regions whose standardized smear positive prevalence was higher than that of the national weighted prevalence (average value). They were Neimeng, Hainan, Xinjiang, Sichuan, Anhui, Ningxia, Hunan, Jiangxi and Hubei.
(2) Trend of Fluctuation of Prevalence
As compared with the first survey in 1979, the standardized prevalence in four provinces (Neimeng, Yunnan, Hebei and Guizhou) increased in some degree and the annual increase rates of the standardized prevalences were 6.2%, 2.5%, 1.9% and 1.3% respectively. The prevalence in other provinces, municipalities and regions were all decreased in some degree. The annual reduction rates of the prevalence of active pulmonary tuberculosis in Beijing and Shanghai were 19.2% and 15.7% respectively. There were four provinces (Fuijan, Shandong, Jiangsu and Jilin) whose annual reduction rate was above 9%.
As compared with 1979, there were four provinces and regions whose smear positive prevalence increased in some degree i.e. Neimeng, Ningxia, Guizhou and Xinjiang; the annual increase rates were 14%, 1.6%, 1.4% and 0.6% respectively. The smear positive prevalence in other provinces, municipalities and regions decreased in some degree. Beijing had the highest annual reduction rate (19%) and Shanghai followed (13.6%). There were seven provinces and region whose annual reduction rates were from 9.4% to 8.2%. Xizang had a higher annual reduction rate of smear positive prevalence (9.1%; 1979-1990); however its annual reduction rate of standardized prevalence of active pulmonary tuberculosis was only 0.1%.
(3) Prevalence by Age Group and Sex
Prevalence by sex: The national prevalences of active and smear positive pulmonary tuberculosis in male were higher than that of female in all three surveys; and the ratios of prevalence between female (as 1) and male were 1.6:1 and 1.8:1 respectively. There were three province and regions (Qinghai, Xinjiang and Yunnan) whose prevalence of male was lower than that of female and the ratios were 0.7:1, 0.8:1 and 0.9:1 respectively. There were four provinces and region (Guangdong, Guangxi, Hubei and Jiangsu) whose prevalence of male is significantly higher than that of female: the ratios were from 4.1:1 to 3.5:1.
Smear positive prevalence in the 15-19 age group: The smear positive prevalence in the 15-19 age group in this survey was quite different with previous surveys. The first survey (1979) revealed that all provinces, municipalities and regions had detected smear positive patient in this age group. In the second survey (1984/85), there were three province and municipalities (namely Shanghai, Fujian and Beijing) who had not detected any smear positive patient in this age group. In this survey (1990), the number of provinces, municipalities and regions who had not detected any smear positive patients in this age group had increased to 10, i.e. Beijing, Shanghai, Zhejiang, Shandong, Guangdong, Guangxi, Yunnan, Ningxia, Qinghai and Hainan.
Smear positive prevalence in the 65-69 age group: Hainan Province had the highest smear positive prevalence (1,587/100,000) in the 65-69 age group; Neimeng, Xinjiang and Jiangxi followed. They were 1.122/100,000, 989/100,000 and 908/100,000 respectively.
As compared with 1979, there were 22 provinces whose smear positive prevalence in the 65-69 age group decreased in some degree. Four provinces namely Anhui, Fujian, Shandong and Hunan had a significant decrease. The amplitudes of decrease from 1979 were 84.2%, 82.0%, 77.2% and 68.6% respectively. On the other hand, there were seven provinces and regions whose smear positive prevalence in this age group increased. The amplitude of increase from 1979 in Jilin, Guizhou, Neimeng and Henan were 261%, 182%, 135% and 124% respectively (Table 20). Neimeng, Xinjiang, Sichuan and Guizhou were also the provinces whose magnitude of tuberculosis raised than 1979.
Ratio of smear positive prevalence between 15-19 (as 1) and 65-69 age group: Henan, Jilin and Hunan had higher ratio above 20 (times); they were 32.9 (times), 27.1 (times) and 21 .2 (times) respectively. Jiangxi Xinjiang, Xizang and Neimeng had medial ratio from 15.1 (times) to 11.0 (times). There were 11 provinces and regions who had a lower ratio (8.8-2.5 times). The other 1O provinces and municipalities had no any patient detced in the 15-19 age group; and Gansu had no any patient detected in the 65-69 age group.
4. Morbidity of Pulmonary Tuberculosis Among city, town and countryside
Among 928 investigation points in the whole country, 743 points (80.1 %) located in countryside; 121 points (13.0%) located in cities and 64 points (6.9%) located in towns.
Situation in the country: The survey revealed that the prevalence, bacteriological
